The present application relates to a display device having a light emitting element of a self-emitting type including an organic layer.
In recent years, as a display device replacing a liquid crystal display, an organic EL display using an organic light emitting element of a self-emitting type including an organic layer is being practically used. Since the organic EL display is of a self-emitting type, the view angle is wider than that of liquid crystal or the like, and the organic EL display has sufficiently high response also to a high-definition high-speed video signal.
With respect to an organic light emitting element, an attempt for improving display performance was made by introducing a resonator structure and controlling light generated by a light emission layer by improving purity of light colors, increasing light emission efficiency, or the like (refer to, for example, WO 01/39554). For example, as illustrated in FIG. 14, an organic light emitting element Z10 of a top emission type that extracts light from a face (top surface) on the side opposite to a substrate employs a structure that an anode electrode Z13, an organic layer Z14, and a cathode electrode Z16 are sequentially stacked over the substrate via a drive transistor ZTr1. Light from the organic layer Z14 is multiple-reflected between the anode electrode Z13 and the cathode electrode Z16. The drive transistor ZTr1 drives the organic light emitting element Z10. A pixel drive circuit is constructed by the drive transistor ZTr1 together with a signal line Z120A and the like. In FIG. 14, Z111 denotes a substrate, Z212 indicates a gate insulating film of the drive transistor ZTr1, Z217 indicates a protection film made of silicon nitride or the like, and Z218 indicates a planarization film made of polyimide or the like. Further, Z17 denotes a metal layer as an auxiliary wiring, Z24 denotes an element isolation insulating layer, Z18 denotes a protection film made of silicon nitride or the like, and Z19 is a sealing substrate made of a transparent material.